Fix No Bootable Device Error in Acer Laptop

                              

1.  Restart your laptop.                                                                          
2.  As soon as you see the "acer" logo coming on the screen, press F2 key.                                                                                                     
3.  It will take you to the bios screen. Now, from the bios settings, change your boot method from UEFI to Legacy. (If you are lucky, you will have this option).                                                      
4.  Press F10 to save and exit bios. Now your laptop will boot normally.                                                                                        

This might not work for some people because this could happen for any reason, like a hard disk failure. If your had disk is damaged, this method won't obviously fix it

source-http://bitmapcake.blogspot.com/2017/09/fix-no-bootable-device-error-in-acer-laptop.html